Functional distribution and <i>dN/dS</i> ratios of the Lost group during <i>Prochlorococcus</i> early genome reduction.

<p><b>A</b>. The maroon area indicates the percentage of the genes that were deleted during the early genome reduction period (branch #1 and branch #2 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0088837#pone-0088837-g003" target="_blank">Fig. 3</a>) in the ancestor-derived <i>Synechococcus</i> orthologs set (ASO). The purple area shows the percentage of the retained genes. COG abbreviations: C: Energy production and conversion; E: Amino acid transport and metabolism; F: Nucleotide transport and metabolism; G: Carbohydrate transport and metabolism; H: Coenzyme metabolism; I: Lipid metabolism; J: Translation, ribosomal structure and biogenesis; K: Transcription; L: DNA replication, recombination and repair; M: Cell envelope biogenesis, outer membrane; O: Posttranslational modification, protein turnover, chaperones; P: Inorganic ion transport and metabolism; R: general function prediction only; S: Function unknown; T: Signal transduction mechanisms; U: Intracellular trafficking and secretion; V: Defense mechanism; NA: no defined COG annotation. <b>B</b>. Bar plot of the average <i>dN/dS</i> ratios of the <i>Prochlorococcus</i> lost genes and the retained genes across functional groups. A subset of the ASO genes whose orthologs were lost in the <i>Prochlorococcus</i> during the early genome reduction period are shown in maroon. A subset of the ASO genes whose orthologs were kept in the <i>Prochlorococcus</i> genomes immediately after the early genome reduction, are shown in purple.